File size: 3,548 Bytes
01d9a06
 
3befc7f
 
 
 
 
 
 
01d9a06
 
1ccfdd4
3aeb4c6
 
 
 
 
 
 
 
 
 
 
 
 
 
 
3e61765
3aeb4c6
 
 
3aacc66
3aeb4c6
 
 
9178ba6
3aeb4c6
 
 
 
 
 
 
93acdc5
3aeb4c6
 
 
 
 
93acdc5
3aeb4c6
 
 
9178ba6
3aeb4c6
 
 
 
 
 
 
 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
---

license: mit

widget:
 - text: 'C T R P N N N T R K S I R I Q R G P G R A F V T I G K I G N M R Q A H C'
 - text: 'C T R P N N N T R K S I H I G P G R A F Y T T G Q I I G D I R Q A Y C' 
 - text: 'C T R P N N N T R R S I R I G P G Q A F Y A T G D I I G D I R Q A H C'
 - text: 'C G R P N N H R I K G L R I G P G R A F F A M G A I G G G E I R Q A H C'

---


# HIV_BERT model



## Table of Contents

- [Summary](#model-summary)

- [Model Description](#model-description)

- [Intended Uses & Limitations](#intended-uses-&-limitations)

- [How to Use](#how-to-use)

- [Training Data](#training-data)

- [Training Procedure](#training-procedure)

  - [Preprocessing](#preprocessing)

  - [Training](#training)

- [Evaluation Results](#evaluation-results)

- [BibTeX Entry and Citation Info](#bibtex-entry-and-citation-info)



## Summary



The HIV-BERT model was trained as a refinement of the [ProtBert-BFD model](https://huggingface.co/Rostlab/prot_bert_bfd) for HIV centric tasks. It was refined with whole viral genomes from the [Los Alamos HIV Sequence Database](https://www.hiv.lanl.gov/content/sequence/HIV/mainpage.html). This pretraining is important for HIV related tasks as the original BFD database contains few viral proteins making it sub-optimal when used as the basis for transfer learning tasks. This model and other related HIV prediction tasks have been published (link).



## Model Description



Like the original [ProtBert-BFD model](https://huggingface.co/Rostlab/prot_bert_bfd), this model encodes each amino acid as an individual token. This model was trained using Masked Language Modeling: a process in which a random set of tokens are masked with the model trained on their prediction. This model was trained using the damlab/hiv-flt dataset with 256 amino acid chunks and a 15% mask rate.



## Intended Uses & Limitations



As a masked language model this tool can be used to predict expected mutations using a masking approach. This could be used to identify highly mutated sequences, sequencing artifacts, or other contexts. As a BERT model, this tool can also be used as the base for transfer learning. This pretrained model could be used as the base when developing HIV-specific classification tasks.



## How to use



[Code snippet of AutoModelForMaskedLM prediction of V3 amino acids.]



## Training Data



The dataset [damlab/HIV_FLT](https://huggingface.co/datasets/damlab/HIV_FLT) was used to refine the original [rostlab/Prot-bert-bfd](https://huggingface.co/Rostlab/prot_bert_bfd). This dataset contains 1790 full HIV genomes from across the globe. When translated, these genomes contain approximately 3.9 million amino-acid tokens.



## Training Procedure



### Preprocessing



As with the [rostlab/Prot-bert-bfd](https://huggingface.co/Rostlab/prot_bert_bfd) model, the rare amino acids U, Z, O, and B were converted to X and spaces were added between each amino acid. All strings were concatenated and chunked into 256 token chunks for training. A random 20% of chunks were held for validation.



### Training



Training was performed with the HuggingFace training module using the MaskedLM data loader with a 15% masking rate. The learning rate was set at E-5, 50K warm-up steps, and a cosine_with_restarts learning rate schedule and continued until 3 consecutive epochs did not improve the loss on the held-out dataset.



## Evaluation Results



[Table of Prot-Bert and HIV-Bert loss on HIV sequence datasets]



## BibTeX Entry and Citation Info



[More Information Needed]